JFK Assassination Forum

There is no need to assume anything. The shells are clearly marked.
It was not just ".38" It was "automatic .38"

lame - Why would Hill guess at the caliber if it is written on the shell?
Add Davis sisters and Benevides to the equation and it gets worse

Gerald Hill | DPD
Mr. HILL. Right. And Poe showed me a Winston cigarette package that contained three spent jackets from shells that
he said a citizen had pointed out to him where the suspect had reloaded his gun and dropped these in the
grass, and that the citizen had picked them up and put them in the Winston package.

Domingo Benavides | CBS Special
"...They were looking all over the place for evidence and everything...and taking fingerprints and what have you...
So--I guess they were gonna just walk off and leave them...not knowing they was there..
and seeing I knew where they was at I walked over and picked up a stick..and picked them up and put them in a Winston package...
I think I picked up 2 and put them in the Winston package and as I was walking back I picked the other one up by hand I believe..."

Four shell casings were recovered from the scene of Officer Tippit's murder. According to the official report, two were found by one witness, and the remaining two by other individuals.

Sisters Virginia and Barbara Davis (also known as Jeanette) each discovered a shell casing in the bushes near the house they rented. However, this is where the chain of custody and the timeline of evidence collection become unclear.

Domingo Benavides was the closest eyewitness to the shooting and had a clear view of where the suspect discarded the shell casings. The Homicide Report, Police Report, and Official Autopsy Report all state that Officer Tippit was struck three times. Yet, four shell casings were recovered.

The first two casings, picked up by Benavides, were entered into evidence and are well-documented.
(though he claimed to have found 3)

The fourth shell was found by Virginia Davis several hours later, after the police had already left the scene. Despite multiple searches of the area earlier in the day, she and her sister Jeanette continued looking and eventually located the casing in the bushes around 5:30 p.m. They contacted the police, and Officer C.N. Dhority returned to the scene, conducted an additional search, and retrieved the shell around 7:00 p.m.

Of the four shell casings, three—identified as Q74, Q75, and Q77—have a relatively consistent and traceable chain of custody, although there are concerns regarding a brief detour made by a “sergeant in the crime scene search section” to the Texas Theater, which complicates the evidence handling process.

It is the third shell casing, designated Q76, that presents the most issues. Its chain of custody is questionable and has led to speculation that Captain Doughty (distinct from Officer Dhority) may never have actually handled it at all.

Again, in common usage, just plain ".38" is assumed to be .38 Special. Just like plain ."357" is assumed to mean ".357 Magnum" and "9mm" is assumed to mean "9mm Parabellum/Luger" Hill actually is saying that the cases are .38 Special

Gil Jesus provides a detailed explanation of the confusion surrounding the shells here:
https://gil-jesus.com/the-tippit-shells/

It is a mess.

A veteran officer knows that shells have markings and would look without assuming.
“the shells at the scene indicate the suspect is armed with an automatic 38 rather than a pistol.”